An analgesic is a drug that relieves pain (analgesia). These “pain killers” are not anesthetics. Anesthetics reversibly eliminate sensation, while analgesics raise the level of sensitivity to pain. Analgesic medications may be administered intravenously, orally, or topically. When these medications enter the bloodstream or digestive tracts, there may be long-term side effects. Analgesic medications applied to the skin are generally safer than those administered internally.
Topical analgesics may be safely used to treat pain due to various conditions. Painful joints may be treated with a gel containing ibuprofen or diclofenac. Capsacin is also used to treat muscle aches. Salonpas® is a topically applied patch that uses capsacin to provide relief from mild pain due to arthritis, joint, hip, and back pain, as well as muscle aches. Lidoderm (5% patches) apply lidocaine (an anesthetic) to the affected area. Lidocaine is also used topically to relieve pain from mouth sores and to numb areas for dental work and minor medical procedures. Bengay is an analgesic heat rub used to relieve muscle and joint pain. The original Bengay contained 15% methyl salicylate and 10% menthol. The muscle pain, ultra-strength Bengay formula comprises 30% methyl salicylate, 10% menthol, and 4% camphor. Ice extra-strength Bengay contains 10% menthol. Muscle pain-no odor Bengay contains 15% triethanolamine salicylate. Arthritis extra-strength Bengay contains 30% methyl salicylate and 8% menthol. Other topical creams manufactured from minerals found in the Dead Sea are somewhat effective arthritis pain relievers.
777 Oil is an Indian topical medicine prepared from the leaves of wrightia tinctoria, a flowering tree found in India. The primary use for this plant is to formulate indigo dyes. The makers of 777 Oil proposed using it to treat various forms of psoriasis. In a reference by Ghosh, et. al., (“Anti-Inflammatory, Analgesic, and Antipyretic Activities of 777 Oil—A Siddha Medicine,” B.M.E.B.D., Vol. VI No. 2 to 4 pp 141-184), the authors claim analgesic properties of the oil. Their conclusions were based upon their inducing a writhing response in mice by injecting them with acetic acid. In some of the mice, arthritis resulted from injections of formaldehyde. 777 Oil was then administered to these mice. The mice upon which the oil was administered were able to stretch more easily than the control group. The authors interpreted this response as analgesia. Unfortunately, these results are inconclusive, and not even suggestive of analgesia. While 777 Oil is used today for treatment of psoriasis, it is not used as a topical analgesic.
Many prescription and over-the-counter topical pain medications are currently sold in drug stores. Lidocaine is very effective when applied to mucous membranes. However, most preparations are effective only for mild pain. There is a long-felt and unfulfilled need for a topical application that would alleviate more severe pain.